Why don't more people include High dividend yield funds in their portfolio?

I've been browsing this thread for a while now and learned a lot, but one thing I'm confused by is why people don't advise putting a reasonable percentage of your retirement funds into REITs or High Divided Yield funds.

I thought they would be great to have because they help grow your account and give you more money to invest. This is especially true for something like a Roth IRA account which limits how much money you can put into it each year.

So what does this community think of my logic? Am I not seeing something? If you do invest in REIT/Divided funds, which have you chosen and why?